I saw a few questions about installing Enterprise Controllers in Logical Domains, and what's possible with that sort of deployment. Here are some answers:
"Is it supported to install the Enterprise Controller in a Logical Domain?"
Yep. The Certified Systems Matrix lists the supported OSes for EC installation, and Oracle VM Server for SPARC is supported (as are some Oracle Solaris Zones).
"Can you use Oracle Solaris Cluster to provide High Availability for an Enterprise Controller installed on a Logical Domain?"
Yes, this is possible. It deserves its own post, so I'll go into more detail on it soon, but yes, it works.
"If I have two Enterprise Controllers installed on Logical Domains, can I have EC 1 discover and manage the LDom for EC 2, and vice versa?"
No. The Agent Controllers installed on EC and PC systems are different from standard Agents, and if you install an Agent from one EC on another EC's system, it's going to get confused.